Microsoft broke the European Union's antitrust regulations by "tying" collaboration tool Teams to its dominant online Office productivity suite, according to preliminary findings from an investigation begun in July 2023.

The EU's antitrust team informed the Redmond-based biz in a Statement of Objections document, and the company told The Register it is willing to make further concessions, thereby staving off the threat of possible legal action and potentially significant fines.

"Microsoft has been tying Teams with its core SaaS productivity applications, thereby restricting competition on the market for communication and collaboration products and defending its market position in productivity software and its suites-centric model from competing suppliers of individual software," the EC said in a statement.

"In particular, the Commission is concerned that Microsoft may have granted Teams a distribution advantage by not giving customers the choice whether or not to acquire access to Teams when they subscribe to their SaaS productivity applications.

"This advantage may have been further exacerbated by interoperability limitations between Teams' competitors and Microsoft's offerings. The conduct may have prevented Teams' rivals from competing, and in turn innovating, to the detriment of customers in the European Economic Area."